Yahoo's share of the U.S. online ad market declined to 9.5 percent last year, from 15.7 percent in 2009, eMarketer said. And while the market overall is expected to grow substantially this year, Yahoo's share will decline further, to 7.4 percent, it predicted.

In the quarter just ended, Yahoo's revenue from display advertising, including traffic acquisition costs, was $535 million, up 2 percent from a year earlier. Its revenue from search, also including acquisition costs, was $461 million, a 1 percent decrease, Yahoo said.

The income figures above include restructuring charges and deal-related expenses. Excluding those charges, Yahoo's net earnings would have been $0.27 per share, it said, ahead of financial analysts' forecast.